Goodbye.
River's kiss was deep and lingering. Every nerve within him shook and sang, every inch of him tensed with the sensation. She began to break away after moments, but with a jerk he drew her closer still, pressing one palm to the back of her neck. He urged with all his desperation for each moment to become longer, willing Time to let them be, just for a day, one more day.
She couldn't know how intensely this kiss seared through to his hearts, branded and crippled him, made his muscles weak with despair. One of their last.
No - truly his last. The last time that he would ever have her before him in the flesh, tangible and radiant. She would never be like this again in memory.
It had been coming and he had felt it. The sharp clarity of her eyes as she used to observe him had become a wondering haze. Each touch and each kiss had become more tentative, more explorative - breathtaking and chilling all at once.
But this morning, when he had simply shown up as always, and she had gazed at him with such expectation and such purity... so very unlike the Melody who had murdered him. So set for their ready-made future. His past.
It caused a weight in him that he had only felt once before and that no person should have to feel twice. Another man had settled into his body and sat there like a rock, like old age and weariness - the man he was to become, when he had lost her to Time.
He abruptly dropped his arms until only their fingers touched, and leant his forehead against her own. Sighs escaped from him as often as breaths.
She took his face in her hands and forced him to meet her stare.
She began to speak, but found she had nothing to soothe him with. His fathomless, ancient blue halos and the dense blackness within them were overpowering.
There would be no arguing, no comfort and no consolation. They reflected the universe, and the universe was a vast, cruel, desolate thing. No matter how far he ran, he would never escape it.
He had to go. He was needed. Always needed.
He wondered that he couldn't force himself to ignore it all, in favour of River. How could he not, at the end, turn his back on the universe, just to stay another day?
"You can't stay, my love," she murmured, caressing his hair softly, "it isn't your nature."
He set his jaw and stared fixedly at the ground. He resented how correct she was. As always.
"What will I have now, without you?" he managed through clenched teeth. He could hear his own voice breaking.
She drew his mouth to hers, and brought warmth back into his body.
"I would like to move forwards knowing that you'll live, and live well. There's more to the universe besides me, love." she grasped his quivering hands in her own, "Run, if you need to keep running. But don't mourn, while I'm happier by the day. And don't be afraid to move forward yourself."
"What do you mean?" anger flared up, betraying itself in his growling tone, "What would I want with anyone but you?"
"Everything I am going to give you. Nine hundred years deserves more than one love interest, I should think, don't you?"
"Never." he spat, "Don't think it."
Time was hurtling away from them. In seven seconds, he was going to run to the TARDIS and across the universe, away from the only soul that had ever settled him in it.
"You know I love you." she smirked, and the eagerness of new adventure was alight in her face. He could see every of their encounters hidden within her, waiting to become, to happen.
He wished that his beginning had been as prepared, as intoxicated as this - that he had been ready to drink up every second. He had wasted too much Time.
He drew an object from his jacket pocket and placed it gently into her hands.
"What's this?"
"My old sonic. Updated." he muttered, eyeing it with aversion. He had dreaded to touch it since the day it had been remade. Giving it to her left with him a sickening sense of finality. It settled astride his already bowed shoulders: the last, awful weight.
He could barely lift his head to take her in for the final time.
"Remember the book." he said.
One last, aching kiss, then he turned on his heel and he ran.
He didn't look back.